Sax is ’scissors’, originally a plural form meaning ’the two knives’, from a common Germanic word for ‘knife’, ‘short sword’, related to Latin saxum, ‘rock’. Whether Saxons are ‘sword-bearers’ or ‘rock people’ is not clear. (Oh, and German Messer comes from Germanic *mati-sahsa – ‘meat-knife!)
Scissors come a long way via French ciseaux from Latin caedere ‘to cut’.
‘To cut with scissors’ is ‘att klippa’, a Nordic word, probably onomatopoetic, also borrowed into English as clip. The homonymous noun klippa 'rock'– English cliff - is not related. The Swedish version comes from Dutch or Low German klippe.
These are the best scissors I’ve ever had.